Apparatus for the roasting of ores or the like



1 1954 A. D. H. L. FASSOTTE APPARATUS FOR THE ROASTING OF ORES OR THE LIKE Filed Feb. 17. 1950 Invento'L Patented Jan. 12, i954 APPARATUS FOR THE ROASTING OF ORES OR THE LIKE Adolphe Denis Henri Leon Fassotte, Neerpelt,

Belgium, assignor to C ompagnie des Metaux dOverbelt-Lommel et de Corphalie S. A., Overpelt-lez-Neerpelt, Belgium Application February 17, 1950, Serial No. 144,633

, Claims priority, application Great Britain i j March 4, 1949 This invention relatesv 1 to an improved 7 apparatus for the roasting of ores or the like in a finely divided form.

In known apparatus serving for the roasting of ore or the like in a finely divided form which is held in suspension and in partial suspension in the gas produced, the air or other oxygencontaining gas required for the roasting operation is generally blown into the reaction cham her through a grating or perforated plate which limits the reaction chamber at its lower part across the entire cross-section.

Such grates or perforated plates have many drawbacks.

They produce considerable losses of head and become easily blocked, thus causing irregularities in the blowing of air. When they are fixed, they do not allow an easy evacuation of sintered blocks which may be formed owing to an accidental or intentionally produced rise of temperature in the reaction zone or simply because the solid material is fed in a wet condition in order to avoid costs of drying, sieving and crushing, in which case the formation of nodules is unavoidable.

According to the present invention, the reaction chamber is constructed at its lower part in such a manner that nodules of roasted ore which accumulate therein take the natural slope, and can be evacuated at will without disturbing the process of roasting which is proceeding in the reaction chamber. Means may be provided at the said lower part permitting the admission of air through the mass of nodules prior to its admission into the roasting region where the grains are held in partial suspension in the gas.

Such means for the admission of air may comprise a capped device provided with passages for the air and extending across a small fraction of the cross-section of the reaction chamber. In addition, air or other oxygen-containing gas may be admitted laterally through the nodules zone into the reaction chamber. Further admission pipes of air may be provided at several points around the reaction chamber, just above the nodules zone, that is at the base of the semisuspension space.

The accompanying drawing shows diagrammatically and by way of example one mode of carrying the invention into effect, applied to the roasting of blendes or pyrites in a finely divided form by suspension and partial or semisuspension of the grains in the gas.

Referring to the drawing, ,1, 9 represent two regions of the reaction chamber, which is pref- 1 Claim. (01. 266-20) erably of cylindrical cross-section; (the lower part of the chamber may have the shape of an inverted truncated cone), 1 is a rotary dustremoving device which throws small sized grains back into the reaction chamber.

At the lower part of f the nodules of solid material accumulate and take their natural slope at t, then fill hoppers y, 7' from which they may be evacuated as required by means of valves Ic, k. a is a lateral admission of blown air. 01 is a central admission of blown air. The air which is admitted through a, fills the space 0, c, then enters through the slopes it, into the pervious mass of nodules. The air which is blown through d enters the same mass through a capped device d which may be provided with holes 0. The total air provided by both inlets arrives finally at the level of the basis of the mass in partial suspension ,2 where it may meet the air coming from a third inlet through the manifold u and the nozzles 0 which blow this air more or less horizontally; all the air passes together through the mass 1 held in partial suspension, then passes through the space y where the grains are held in suspension and escapes through the rotary device Z and conduit m. The device 1 which is not essential for the carrying of the present invention into effect, comprises blades rotating around a vertical central axis; the gaseous fluid enters at the periphery of the device from the reaction chamber 9 is directed towards its central region against the centrifugal force and leaves towards the periphery into the conduit m. The centrifugal force, developed by the rotation of the rotary member throws back the coarsest particles into the reaction space.

The blende or pyrite 'which is fed from a hopper 12 through a measuring screw p into the reaction chamber, is roasted while held in a state of suspension in the space 9 and in a state of semisuspension in the space i. The nodules and sintered material accumulate at 9', 7', Whilst the material completely roasted is evacuated, the finest particles through m with the gases, the coarser particles by overflow through a conduit h into a hopper i which may be emptied as required through a valve k1.

A manifold u for blown air feeds a series of nozzles '12 uniformly distributed at the periphery of the reaction chamber for blowing air into the lower region of the zone f where grains are held in partial suspension. Dampers (not shown) allow of distributing the total air serving for the roasting between a, d and u so as simultaneously to obtain a great uniformity in the air distribution and a minimum loss of head.

An apl aigratus'g for thegroastirig} of; orfe-in a finely; divided farm-11mm suspension and partial suspension in a gas, having a reaction chamber for, the ore, means for feeding ore into the reaction chamber, a lower chamber largely;belowandasurrounding the lower part of the reaction chamber; larger than the reaction chamber and freely communicating with the reaction chamber; into which lower chamber nodulesloj-ore carifallfrom' the reaction chamber and accumulate, means for admitting into the reactionchamber air above the lower chamber substantially at the level of separation between the reaction: charmer; and;

the lower chamber, means for admitting air into. the lower chamber and then into the reaction chamber, a central admission of air throu'gh the lower chamber, means for evacuating nodules oi deer-ma ine weer part ofthe" fewer chamber,-

means for evacuating coarse roasted ore from the reaction chamber at a level located between the feeding means for the ore and the upper part of the lbv'i ie'r chamber, and? means for" eya'cuating fine-roasted'ore acme upper part'of the reaction chamber.

ADOLPHE DENIS HENRI LEON FASSO'ITE.

R ferences Cited in the file of this patent UNITED STATES PATENTS OTHER REFERENCES Kite and Roberts, Chemical Engineering, December 1 94?, pages= 112-115; 

